Hinge device and electronic device using hinge device

ABSTRACT

The present invention provides an object a novel hinge device which is extremely valuable as a commercial product and an electronic instrument using the hinge device. 
     A hinge device for pivoting a first member ( 1 ) and a second member ( 2 ) to be rotatably opened and closed is characterized in that when the second member ( 2 ) kept under a coupled and closed condition is opened to the first member ( 1 ), in a rotational range A 1  from the coupled and closed position P 1  to a predetermined open angle position P 2  rotated in an open direction, a closing rotational biasing effect is generated for automatically closing the second member ( 2 ) to the coupled and closed position P 1  relative to the first member ( 1 ), and when the second member ( 2 ) is manually rotated in the open direction exceeding the predetermined open angle position P 2  to the first member ( 1 ), an open rotational biasing effect is generated for automatically opening the second member ( 2 ) to a predetermined open angle position P 3  relative to the first member ( 1 ).

FIELD OF THE INVENTION

The present invention relates to a hinge device and an electronicinstrument using the hinge device.

BACKGROUND ART

For example, a portable phone as a typical example of a portableelectronic instrument is of collapsible type in which a portable phonebody (a body portion and a joint portion) is collapsible.

This collapsible type is popular in aspects of preventing a switch frommalfunctioning, making the phone compact when the phone is collapsed (tokeep a display area sufficient), a variety of designs and the like.

Accordingly, while ones' eyes are kept on this collapsible type portablephone more and more, there are demands to provide a more useful phone.

The present application has made further experiments and studiesrepeatedly with respect to the above-described hinge device and hasdeveloped a novel hinge device and an electronic instrument using thehinge device which is more valuable as a commercial product.

DISCLOSURE OF THE INVENTION

The essence of the present invention will be described with reference tothe accompanying drawings.

Also, the invention relates to a hinge device for pivoting a firstmember 1 and a second member 2 to be rotatably opened and closed,characterized by comprising a first joint member 3 coupled with thefirst member 1 in a rotation prevented condition and a second jointmember 4 coupled relatively rotatably to the first joint member 3 andcoupled with the second member 2 in a rotation prevented condition,wherein a cam portion 10 is provided to either one of the first jointmember 3 and the second joint member 4, a cam engagement portion 11which engages with the cam portion 10 is provided to the other, at leastone of the cam portion 10 and the cam engagement portion 11 is providedslidably in the engagement and disengagement direction, an engagementbiasing member 12 is provided for biasing at least one of the camportion 10 and the cam engagement portion 11 in the engagementdirection, when the second member 2 kept under the coupled and closedcondition is opened to the first member 1, in a rotational range A1 to apredetermined open angle position P2 rotated in the open direction fromthe coupled and closed position P1, the cam portion 10 and the camengagement portion 11 are biased by said engagement biasing member 12and in dropping engagement with each other whereby a closing rotationbiasing effect is generated for automatically closing the second member2 to the coupled and closed position P1 relative to the first member 1,a rotational biasing member 13 is provided for biasing at lest one ofthe cam portion 10 and the cam engagement portion 11 in a rotationaldirection, when the second member 2 is manually rotated in the opendirection relative to the first member 1 exceeding the predeterminedopen angle position P2, the cam portion 10 and the cam engagementportion 11 are biased by the rotational biasing member 13 and are notdisengaged from each other but rotated together under the engagementcondition so that the open rotational biasing effect is generated forautomatically opening the second member 2 to the predetermined openangle position P3 relative to the first member 1, a retainer member 8for releasably retaining said cam portion 10 or the cam engagementportion 11 is provided in a rotation prevented manner in either one ofsaid first joint member 3 and said second joint member 4, under thecondition that the retainer member 8 is retained at the cam portion 10or the cam engagement portion 11, the cooperative rotation of the camportion 10 and the cam engagement portion 11 by said rotational biasingmember 13 is prevented, when the retainer member 8 is disengaged fromthe cam portion 10 or the cam engagement portion 11, the cooperativerotation between the cam portion 10 and the cam engagement portion 11 bythe rotational biasing member 13 is allowed, and the retention force ofthe retainer member 8 relative to the cam portion 10 or the camengagement portion 11 is set up to such a retention force that theretainer member 8 is not disengaged from the cam portion 10 or the camengagement portion 11 by the biasing force of said rotational biasingmember 13, and when the second member 2 is manually rotated in theopening direction exceeding the predetermined open angle position P2against the closing rotational biasing force by the cam portion 10 andthe cam engagement portion 11 relative to the first member 1, theretainer member 8 may be disengaged from the cam portion 10 or the camengagement portion 11.

Also, the invention relates to a hinge device for pivoting a firstmember 1 and a second member 2 to be rotatably opened and closed,characterized by comprising a first joint member 3 coupled with thefirst member 1 in a rotation prevented condition and a second jointmember 4 coupled relatively rotatably to the first joint member 3 andcoupled with the second member 2 in a rotation prevented condition,wherein a cam portion 10 is provided to either one of the first jointmember 3 and the second joint member 4, a cam engagement portion 11which engages with the cam portion 10 is provided to the other, at leastone of the cam portion 10 and the cam engagement portion 11 is providedslidably in the engagement and disengagement direction, an engagementbiasing member 12 is provided for biasing at least one of the camportion 10 and the cam engagement portion 11 in the engagementdirection, when the second member 2 kept under the coupled and closedcondition is opened to the first member 1, in a rotational range A1 to apredetermined open angle position P2 rotated in the open direction fromthe coupled and closed position P1, the cam portion 10 and the cameengagement portion 11 are biased by said engagement biasing member 12and in dropping engagement with each other whereby a closing rotationbiasing effect is generated for automatically closing the second member2 to the coupled and closed position P1 relative to the first member 1,a rotational biasing member 13 is provided for biasing at least one ofthe cam portion 10 and the cam engagement portion 11 in a rotationaldirection, when the second member 2 is manually rotated in the opendirection relative to the first member 1 exceeding the predeterminedopen angle position P2, the cam portion 10 and the cam engagementportion 11 are biased by the rotational biasing member 13 and are notdisengaged from each other but rotated together under the engagementcondition so that the open rotational biasing effect is generated forautomatically opening the second member 2 to the predetermined openangle position P3 relative to the first member 1, in a rotational rangeA2 to the predetermined open angle position P2 rotated in the closingdirection from a position where the second member 2 is opened to thefirst member 1, the cam portion 10 and the cam engagement portion 11 aredisengaged from each other, an apex portion of the cam portion 10 and anapex portion of the cam engagement portion 11 are in abutment with eachother by the bias of the engagement biasing member 12 to generate africtional resistance to thereby generate a free stop effect for holdingthe second member 2 to the first member 1 at any desired open angleposition, a retainer member 8 for releasably retaining said cam portion10 or the cam engagement portion 11 is provided in a rotation preventedmanner in either one of said first joint member 3 and said second jointmember 4, under the condition that the retainer member 8 is retained atthe cam portion 10 or the cam engagement portion 11, the cooperativerotation of the cam portion 10 and the cam engagement portion 11 by saidrotational biasing member 13 is prevented, when the retainer member 8 isdisengaged from the cam portion 10 or the cam engagement portion 11, thecooperative rotation between the cam portion 10 and the cam engagementportion 11 by the rotational biasing member 13 is allowed, and theretention force of the retainer member 8 relative to the cam portion 10or the cam engagement portion 11 is set up to such a retention forcethat the retainer member 8 is not disengaged from the cam portion 10 orthe cam engagement portion 11 by the biasing force of said rotationalbiasing member 13, and when the second member 2 is manually rotated inthe opening direction exceeding the predetermined open angle position P2against the closing rotational biasing force by the cam portion 10 andthe cam engagement portion 11 relative to the first member 1, theretainer member 8 may be disengaged from the cam portion or the camengagement portion 11.

Also, the invention relates to the hinge device according to any one ofclaims 6 and 7, further characterized in that an engagement concaveportion 9 for fitting and retaining said retainer member 8 is providedin said cam portion 10 or said cam engagement portion 11, and a tapersurfacer 8 a is formed in an insertion portion of the retainer member 8to be inserted into said engagement concave portion 9 whereby aretention force of the retainer member 8 to said engagement concaveportion 9 is set up to such a retention force that the retainer member 8is disengaged from the cam portion 10 or the cam engagement portion 11when the second member 2 is manually rotated relative to the firstmember 1 in the open direction exceeding the predetermined open angleposition P2 against the closing rotation biasing force by the camportion 10 and the cam engagement portion 11.

Also, the invention relates to the hinge device according to any one ofclaims 6 and 7, further characterized in that said retainer member 8 isslidingly moved by a depression operation of a depression button portion26 so that the retention to said closing structure portion 5 isreleased.

Also, the invention relates to a hinge device for pivoting a firstmember 1 and a second member 2 to be rotatably opened and closed,characterized by comprising a first hinge member H1 provided in a firstpivot portion 25A provided in either one of right and left positions ofa pivot joint portion 25 between said first member 1 and said secondmember 2 and a second hinge member H2 provided in a second pivot portion25B provided in the other position, wherein said first hinge member H1is composed of a first joint member 3 coupled to the first member 1 orthe second member 2 and a second joint member 4 coupled to the secondmember 2 or the first member 1, a cam portion 10 is provided to eitherone of the first joint member 3 and the second joint member 4 of saidfirst hinge member H1, a cam engagement portion 11 which engages withthe cam portion 10 is provided to the other, at least one of the camportion 10 and the cam engagement portion 11 is provided slidably in theengagement and disengagement direction, an engagement biasing member 12is provided for biasing at least one of the cam portion 10 and the camengagement portion 11 in the engagement direction, when the secondmember 2 kept under the coupled and closed condition is opened to thefirst member 1, in a rotational range A1 to a predetermined open angleposition P2 rotated in the open direction from the coupled and closedposition P1, the cam portion 10 and the cam engagement portion 11 arebiased by said engagement biasing member 12 and in dropping engagementwith each other whereby a closing rotation biasing effect is generatedfor automatically closing the second member 2 to the coupled and closedposition P1 relative to the first member 1, a rotation biasing member 13is provided in said second hinge member H2 for biasing at least one ofthe cam portion 10 and the cam engagement portion 11 in a rotationaldirection, the cam portion 10 and the cam engagement portion 11 arebiased by the rotational biasing member 13 and are not disengaged fromeach other but rotated together under the engagement condition so thatthe open rotational biasing effect is generated for automaticallyopening the second member 2 to the predetermined open angle position P3relative to the first member 1, a retainer member 8 for releasablyretaining said cam portion 10 or the cam engagement portion 11 isprovided in either one of said first joint member 3 and said secondjoint member 4 of said first hinge member H1, under the condition thatthe retainer member 8 is retained at the cam portion 10 or the camengagement portion 11, the cooperative rotation of the cam portion 10and the cam engagement portion 11 by said rotation biasing member 13 isprevented, when the retainer member 8 is disengaged from the cam portion10 or the cam engagement portion 11, the cooperative rotation betweenthe cam portion 10 and the cam engagement portion 11 by the rotationalbiasing member 13 is allowed, and said retainer member 8 is slidinglymoved by a depression operation of a depression button portion 26provided in either one of the first joint member 3 and the second jointmember 4 so that the retention to said cam portion 10 or the camengagement portion 11 is released.

Also, the invention relates to a hinge device for pivoting a firstmember 1 and a second member 2 to be rotatably opened and closed,characterized by comprising a first hinge member H1 provided in a firstpivot portion 25A provided in either one of right and left positions ofa pivot joint portion 25 between said first member 1 and said secondmember 2 and a second hinge member H2 provided in a second pivot portion25B provided in the other position, wherein said first hinge member H1is composed of a first joint member 3 coupled to the first member 1 orthe second member 2 and a second joint member 4 coupled to the secondmember 2 or the first member 1, a cam portion 10 is provided to eitherone of the first joint member 3 and the second joint member 4 of saidfirst hinge member H1, a cam engagement portion 11 which engages withthe cam portion 10 is provided to the other, at least one of the camportion 10 and the cam engagement portion 11 is provided slidably in theengagement and disengagement direction, an engagement biasing member 12is provided for biasing at least one of the cam portion 10 and the camengagement portion 11 in the engagement direction, when the secondmember 2 kept under the coupled and closed condition is opened relativeto said first member 1, in a rotational range A1 to a predetermined openangle position P2 rotated in the open direction from the coupled andclosed position P1, the cam portion 10 and the cam engagement portion 11are biased by said engagement biasing member 12 and in droppingengagement with each other whereby a closing rotation biasing effect isgenerated for automatically closing the second member 2 to the coupledand closed position P1 relative to the first member 1, a rotationalbiasing member 13 is provided in said second hinge member H2 for biasingat least one of the cam portion 10 and the cam engagement portion 11 ina rotational direction, the cam portion 10 and the cam engagementportion 11 are biased by the rotational biasing member 13 and are notdisengaged from each other but rotated together under the engagementcondition so that the open rotational biasing effect is generated forautomatically opening the second member 2 to the predetermined openangle position P3 relative to the first member 1, in a rotational rangeA2 to the predetermined open angle position P2 rotated in the closingdirection from a position where the second member 2 is opened to thefirst member 1, the cam portion 10 and the cam engagement portion 11 aredisengaged from each other, an apex portion of the cam portion 10 and anapex portion of the cam engagement portion 11 are in abutment with eachother by the bias of the engagement biasing member 12 to generate africtional resistance to thereby generate a free stop effect for holdingthe second member 2 to the first member 1 at any desired open angleposition, a retainer member 8 for releasably retaining said cam portion10 or the cam engagement portion 11 is provided in either one of saidfirst joint member 3 and said second joint member 4 of said first hingemember H1, under the condition that the retainer member 8 is retained atthe cam portion 10 or the cam engagement portion 11, the cooperativerotation of the cam portion 10 and the cam engagement portion 11 by saidrotation biasing member 13 is prevented, when the retainer member 8 isdisengaged from the cam portion 10 or the cam engagement portion 11, thecooperative rotation between the cam portion 10 and the cam engagementportion 11 by the rotational biasing member 13 is allowed, and saidretainer member 8 is slidingly moved by a depression operation of adepression button portion 26 provided in either one of the first jointmember 3 and the second joint member 4 so that the retention to said camportion 10 or the cam engagement portion 11 is released.

Also, the invention relates to a hinge device for pivoting a firstmember 1 and a second member 2 to be rotatably opened and closed,characterized by comprising a first hinge member H1 provided in a firstpivot portion 25A provided in either one of right and left positions ofa pivot joint portion 25 between said first member 1 and said secondmember 2 and a second hinge member H2 provided in a second pivot portion25B provided in the other position, wherein said first hinge member H1is composed of a first joint member 3 coupled with the first member 1 orthe second member 2 and a second joint member 4 coupled with the secondmember 2 or the first member 1, a cam portion 10 is provided to eitherone of the first joint member 3 and the second joint member 4 of saidfirst hinge member H1, a cam engagement portion 11 which engages withthe cam portion 10 is provided to the other, at least one of the camportion 10 and the cam engagement portion 11 is provided slidably in theengagement and disengagement direction, an engagement biasing member 12is provided for biasing at least one of the cam portion 10 and the camengagement portion 11 in the engagement direction, when the secondmember 2 kept under the coupled and closed condition is opened to thefirst member 1, in a rotational range A1 to a predetermined open angleposition P2 rotated in the open direction from the coupled and closedposition P1, the cam portion 10 and the cam engagement portion 11 arebiased by said engagement biasing member 12 and in dropping engagementwith each other whereby a closing rotation biasing effect is generatedfor automatically closing the second member 2 to the coupled and closedposition P1 relative to the first member 1, a rotation biasing member 13is provided in said second hinge member H2 for biasing at least one ofthe cam portion 10 and the cam engagement portion 11 in a rotationaldirection, when the second member 2 is manually rotated in the opendirection exceeding to the predetermined open angle position P2 relativeto the first member 1, the cam portion 10 and the cam engagement portion11 are biased by the rotational biasing member 13 and are not disengagedfrom each other but rotated together under the engagement condition sothat the open rotational biasing effect is generated for automaticallyopening the second member 2 to the predetermined open angle position P3relative to the first member 1, a retainer member 8 for releasablyretaining said cam portion 10 or the cam engagement portion 11 isprovided in either one of said first joint member 3 and said secondjoint member 4 of said first hinge member H1, under the condition thatthe retainer member 8 is retained at the cam portion 10 or the camengagement portion 11, the cooperative rotation of the cam portion 10and the cam engagement portion 11 by said rotational biasing member 13is prevented, when the retainer member 8 is disengaged from the camportion 10 or the cam engagement portion 11, the cooperative rotationbetween the cam portion 10 and the cam engagement portion 11 by therotational biasing member 13 is allowed, a retention force of theretainer member 8 to said cam portion 10 or said cam engagement portion11 is set up so that the retainer member 8 is not disengaged from thecam portion 10 or the cam engagement portion 11 by the biasing force ofsaid rotational biasing member 13, and the retainer member 8 may bdisengaged from the cam portion 10 or the cam engagement portion 11 whenthe second member 2 is manually rotated in the open direction exceedingthe predetermined open angle position P2 against the closing rotationalbiasing force by said cam portion 10 and said cam engagement portion 11relative to said first member 1.

Also, the invention relates to a hinge device for pivoting a firstmember 1 and a second member 2 to be rotatably opened and closed,characterized by comprising a first hinge member H1 provided in a firstpivot portion 25A provided in either one of right and left positions ofa pivot joint portion 25 between said first member 1 and said secondmember 2 and a second hinge member H2 provided in a second pivot portion25B provided in the other position, wherein said first hinge member H1is composed of a first joint member 3 coupled with the first member 1 orthe second member 2 and a second joint member 4 coupled with the secondmember 2 or the first member 1, a cam portion 10 is provided to eitherone of the first joint member 3 and the second joint member 4 of saidfirst hinge member H1, a cam engagement portion 11 which engages withthe cam portion 10 is provided to the other, at least one of the camportion 10 and the cam engagement portion 11 is provided slidably in theengagement and disengagement direction, an engagement biasing member 12is provided for biasing at least one of the cam portion 10 and the camengagement portion 11 in the engagement direction, when the secondmember 2 kept under the coupled and closed condition is opened to thefirst member 1, in a rotational range A1 to a predetermined open angleposition P2 rotated in the open direction from the coupled and closedposition P1, the cam portion 10 and the cam engagement portion 11 arebiased by said engagement biasing member 12 and in dropping engagementwith each other whereby a closing rotation biasing effect is generatedfor automatically closing the second member 2 to the coupled and closedposition P1 relative to the first member 1, a rotational biasing member13 is provided in said second hinge member H2 for biasing at least oneof the cam portion 10 and the cam engagement portion 11 in a rotationaldirection, when the second member 2 is manually rotated in the opendirection exceeding to the predetermined open angle position P2 relativeto the first member 1, the cam portion 10 and the cam engagement portion11 are biased by the rotational biasing member 13 and are not disengagedfrom each other but rotated together under the engagement condition sothat the open rotational biasing effect is generated for automaticallyopening the second member 2 to the predetermined open angle position P3relative to the first member 1, in a rotational range A2 to thepredetermined open angle position P2 rotated in the closing directionfrom a position where the second member 2 is opened to the first member1, the cam portion 10 and the cam engagement portion 11 are disengagedfrom each other, an apex portion of the cam portion 10 and an apexportion of the cam engagement portion 11 are in abutment with each otherby the bias of the engagement biasing member 12 to generate a frictionalresistance to thereby generate a free stop effect for holding the secondmember 2 to the first member 1 at any desired open angle position, aretainer member 8 fore releaseably retaining said cam portion 10 or thecam engagement portion 11 is provided in either one of said first jointmember 3 and said second joint member 4 of said first hinge member H1,under the condition that the retainer member 8 is retained at the camportion 10 or the cam engagement portion 11, the cooperative rotation ofthe cam portion 10 and the cam engagement portion 11 by said rotationbiasing member 13 is prevented, when the retainer member 8 is disengagedfrom the cam portion 10 or the cam engagement portion 11, thecooperative rotation between the cam portion 10 and the cam engagementportion 11 by the rotational biasing member 13 is allowed, a retentionforce of the retainer member 8 to said cam portion 10 or said camengagement portion 11 is set up so that the retainer member 8 is notdisengaged from the cam portion or the cam engagement portion by thebiasing force of said rotational biasing member 13 and the retainermember 8 may be disengaged from the cam portion 10 or the cam engagementportion 11 when the second member 2 is manually rotated in the opendirection exceeding the predetermined open angle position P2 against theclosing rotational biasing force by said cam portion 10 and said camengagement portion 11 relative to said first member.

Also, the invention relates to an electronic equipment using the hingedevice according to any one of claims 19 and 20, further characterizedin that an engagement concave portion 9 for fitting and retaining saidretainer member 8 is provided in said cam portion 10 or said camengagement portion 11, and a taper surface 8 a is formed in an insertionportion of the retainer member 8 to be inserted into said engagementconcave portion 9 whereby a retention force of the retainer member 8 tosaid engagement concave portion 9 is set up to such a retention forcethat the retainer member 8 is disengaged from the cam portion 10 or thecam engagement portion 11 when the second member 2 is manually rotatedrelative to the first member 1 in the open direction exceeding thepredetermined open angle position P2 against the closing rotationbiasing force by the cam portion 10 and the cam engagement portion 11.

Also, the invention relates to the hinge device according to any one ofclaims 6 to 9, 13, 14, and 19 to 21, further characterized in that abody portion provided with an opening portion 14 and a joint portionprovided with a display image filed 15 are coupled with each other anddisposed to cover the operating portion 14 when said operating portion14 is not operative, having a hinge device for coupling said bodyportion and said joint portion rotatably so that said joint portion isrotated horizontally or in a rising manner from the coupled condition toexpose the operating portion or the joint portion may be rotated aroundits own axis to be turned inside out, wherein said body portion is usedas said first member 1 or said second member 2 and said joint portion isused as said second member 2 or said first member 1 in this hingedevice.

With the above-described structure, it is possible to provide a novelhinge device that may enhance remarkably the operationability of thecommercial product produced by pivotally coupling the first member andsecond member such as performing extremely easily and quickly theopening operation.

Also, in the case where a hinge structure (double hinge structure)composed of the first hinge member and the second hinge member areadopted as the hinge device arranged in a pivot joint portion betweenthe first member and the second member, the pivot joint portion betweenthe first member and the second member for arranging this hinged deviceis divided right and left and each pivot portion (first pivot portionand second pivot portion) may be reduced in size so that a vacant spacemay be produced between the right and left pivot portions. It istherefore possible to keep a sufficient space, for example, to arrangewirings for electrically connecting electronic parts disposed in thefirst member and electronic parts disposed in the second member to eachother. In addition, it is possible to provide a novel hinge device thatmay enhance remarkably the operationability of the commercial productproduced by pivotally coupling the first member and second member suchas performing extremely easily and quickly the opening operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrative view of use condition of a first embodiment.

FIG. 2 is a perspective view showing the first embodiment.

FIG. 3 is an illustrative view of a primary part of the firstembodiment.

FIG. 4 is an exploded perspective view of the first embodiment.

FIG. 5 is an illustrative cross-sectional view of the primary part ofthe first embodiment.

FIG. 6 is an illustrative cross-sectional view of the primary part ofthe first embodiment.

FIG. 7 is an illustrative view of the primary part of the firstembodiment.

FIG. 8 is a cross-sectional view taken along the line A-A of FIG. 7.

FIG. 9 is an end view of the primary part of the first embodiment.

FIG. 10 is an illustrative view of the primary part of the firstembodiment.

FIG. 11 is an exploded perspective view of the primary part of the firstembodiment.

FIG. 12 is an illustrative cross-sectional view of the primary part ofthe first embodiment.

FIGS. 13( a) to 13(c) are schematic views of the operation of theprimary part of the first embodiment.

FIGS. 14( a) to 14(c) are schematic views of the operation of theprimary part of the first embodiment.

FIG. 15 is a schematic view of the operation of the first embodiment.

FIG. 16 is a schematic view of the operation of the first embodiment.

FIG. 17 is an illustrative view of use condition of a second embodiment.

FIG. 18 is a perspective view showing the second embodiment.

FIG. 19 is an exploded perspective view of a primary part of the secondembodiment.

FIG. 20 is an exploded perspective view of the primary part of thesecond embodiment.

FIG. 21 is an illustrative cross-sectional view of the primary part ofthe second embodiment.

FIG. 22 is an illustrative cross-sectional view of the primary part ofthe second embodiment.

FIG. 23 is an illustrative cross-sectional view of the primary part ofthe second embodiment.

FIG. 24 is an illustrative cross-sectional view of the primary part ofthe second embodiment.

FIG. 25 is an illustrative view of the primary part of the secondembodiment.

FIG. 26 is an illustrative view of the primary part of the secondembodiment.

FIG. 27 is an end view of the primary part of the second embodiment.

FIG. 28 is an end view of the primary part of the second embodiment.

FIG. 29 is an exploded perspective view of the primary part of thesecond embodiment.

FIGS. 30( a) to 30(c) are schematic views of the operation of theprimary part of the second embodiment.

FIGS. 31( a) to 31(c) are schematic views of the operation of theprimary part of the second embodiment.

FIG. 32 is a schematic view of the operation of the second embodiment.

BEST MODE FOR EMBODYING THE INVENTION

A best possible mode for embodying the invention (how to embody theinvention in the best mode) will now be described in brief on the basisof the drawings while showing the operational effect of the presentinvention.

According to the present invention, when a second member 2 kept underthe coupled and closed condition is opened to a first member 1, in arotational range A1 from the coupled and closed position P1 to apredetermined open angle position P2 rotated in the open direction, aclosing rotational biasing effect is generated to automatically closethe second member 2 to the coupled and closed position P1 relative tothe first member 1. Also, when the second member 2 is manually rotatedin the open direction relative to the first member 1 exceeding theabove-described predetermined open angle position P2, an open rotationalbiasing effect is generated to automatically open the second member 2 upto a predetermined open angle position P3 relative to the first member1.

Namely, when the second member 2 is manually rotated in the openingdirection exceeding the predetermined open angle position P2 relative tothe first member 1, the second member 2 is automatically opened to thepredetermined open angle position P3.

Accordingly, in the case where the hinge device according to the presentinvention is applied to, for example, the above-described collapsibletype portable electronic equipment which is constituted by pivotallycoupling the body portion and the joint portion with each other, forexample, a finger of a hand holding the phone is inserted between thebody portion and the joint portion in use so that the joint portion isrotated in the open direction relative to the body portion and the jointportion is automatically opened due to the open rotational biasingeffect. Thus, the opening operation of the joint portion may readily andquickly be attained, which is extremely useful.

Also, in the case where, in the rotational range A2 from the positionwhere the second member 2 is opened relative to the first member 1 tothe above-described predetermined open angle position P2 rotated in theclosing direction, a free stop effect is generated to hold the secondmember 2 in any desired open angle position relative to the first member1, it is possible to use the phone while stopping the second member 2relative to the first member 1 in any desired angle of the phone whichis easy to use. This is much more useful.

EMBODIMENT 1

A specific embodiment 1 of the present invention will be described withreference to FIGS. 1 to 16.

The embodiment 1 show the case where a hinge device H according to thepresent invention is applied to a collapsible type portable phone asshown in FIG. 1. The hinge device H according to the present inventionis applied to a pivot mechanism in which a body portion provided with anoperating portion 14 is used as a first member 1 and a joint portionprovided with a display image field 15 is used as a second member 2 tomake it possible to take the condition from the closed condition wherethe first member 1 and the second member 2 are coupled with each otherto the open condition (busy condition) where the second member 2 isrotated to, for example, 120 degrees.

Then, when the second member 2 kept under the coupled and closedcondition is opened to a first member 1, in a rotational range A1 fromthe coupled and closed position P1 to a predetermined open angleposition P2 rotated in the open direction, a closing rotational biasingeffect is generated to automatically close the second member 2 to thecoupled and closed position P1 relative to the first member 1 (see FIG.15), when the second member 2 is manually rotated in the open directionrelative to the first member 1 exceeding the above-describedpredetermined open angle position P2, an open rotational biasing effectis generated to automatically open the second member 2 at once up to apredetermined open angle position P3 (maximum open angle position)relative to the first member 1 (see FIG. 15), and furthermore, in arotational range A2 from the position where the second member 2 isopened to the first member 1 to the above-described predetermined openangle position P2 rotated in the closing direction, where the hand isreleased from the second member 2, the second member 2 stops in thereleased position to realize a free stop condition without any shake(see FIG. 16).

More specifically, in the present embodiment, a mounting hole 1 a isprovided in a proximal portion of the first member 1, a mounting hole 2a is provided adjacent to and in communication with the mounting hole 1a also in a proximal portion of the second member 2, and the hingedevice H according to the present invention constituted into an axialpart is applied to the mounting holes 1 a, 2 a, respectively.

A casing 16 is fixed to the body portion 1 (first member) as a jointportion constituting a part of a first joint member 3 having a rotationpreventing shape through the above-described mounting hole 1 a, and amember disposed in an exposed condition on one end side of this casing16 is fixed as a mounting portion 17 constituting a part of a secondjoint member 4 through the mounting hole 2 a to the joint portion 2(second member) under the rotation prevented condition. This casing 16has an octagonal shape in cross section as shown. This is adapted toattain the firm rotation preventing structure to the body portion 1. Atthe same time, the octagonal shape is adapted as a shape which allowsthe parts to be received effectively in its interior while providing therotation preventing structure.

An axial member 18 is provided at an inner hole 17 a of theabove-described mounting portion 17 under the rotation preventedcondition to constitute the second joint member 4 provided with a camportion 10 at its tip end portion.

The axial member 18 relating to this second joint member 4 is adapted sothat the cam portion 10 is disposed rotatably within the casing 16relating to the first joint member 3.

A closing member 19 is disposed on the other end side of the casing 16relating to the first joint member 3, and furthermore, an engagementmember 20 having a cam engagement portion 11 facing and engaging the camportion 10 of the above-described second joint member 4 in a concave andconvex manner is provided within the casing 16. This engagement member20 is provided rotatably within the casing 16 and at the same timeprovided slidably in the engagement and disengagement direction withinthe casing 16.

A coiled spring 12 for biasing in the engaging direction is provided asan engagement biasing member 12 within the casing 16 between theengagement member 20 having this cam engagement portion 11 and theclosing member 19.

When the joint portion 2 kept under the coupled and closed condition isopened to the body portion 1 by this engagement biasing member 12, inthe rotational range A1 from the coupled and closed position P1 to thepredetermined open angle position P2 rotated in the open direction, thecam portion 10 and the cam engagement portion 11 are slipped down andengaged with each other by biasing by the engagement biasing member 12so that the closing rotational biasing effect for automatically closingthe joint portion 2 up to the coupled and closed position P1 relative tothe body portion 1 is generated. (This is referred to as the closingstructure portion 5 in the claims).

On the other hand, a torque spring 13 is provided as a rotationalbiasing member 13 to the axial member 18 having the cam portion 10, theother end portion of the rotational biasing member 13 is coupled with ajoint member 21 to be disposed under a rotation prevented conditionwithin the casing 16, and accordingly, a biasing force for urging therotational biasing member 16 to rotate the casing 16 in turn functionsas a biasing force for rotating the axial member 18 (cam portion 10) bykeeping the condition that the casing 16 is fixed.

When the joint portion 2 is manually rotated to the body portion 1exceeding the predetermined open angle position P2 in the openingdirection by this rotational biasing member 13, the cam portion 10 andthe cam engagement portion 11 are biased by the rotational biasingmember 13 and rotated together under the engagement condition withoutdisengagement therebetween as a closing structure portion 5 so that theopen rotational biasing effect is generated to automatically release thejoint portion 2 up to the predetermined open angle position P3 relativeto the body portion 1. (This is referred to as an opening structureportion 6 in the claims.)

Also, the cam engagement portion 11 is structured so that V-shapedconcave portions are formed at diametrically 180 degrees oppositepositions, these concave portions are used as engagement portions withwhich the above-described cam portion 10 engages, and an apex portion(end face portion) of the cam portion 10 is brought into contact with anapex portion (end face portion) between the concave portions in therange of disengagement by the pressure force by the engagement biasingmember 12.

In the present embodiment, a frictional resistance increasing means isprovided for increasing a frictional resistance between the apex portionof the cam portion 10 and the apex portion of the cam engagement portion11, and when the apex portion of the cam portion 10 and the apex portionof the cam engagement portion 11 are brought into abutment with eachother, the engagement is held at a stop position by the increase of therotational resistance due to the frictional resistance increasing meansand the pressure force of the engagement biasing member 12 so far as themembers are not moved by hands even if the rotational biasing force ofthe rotational biasing member 13 is applied.

Namely, the frictional resistance increasing means is structured so thatthe abutment area between the apex portion of the cam portion 10 and theapex portion of the cam engagement portion 11 is formed to be increased,whereby the frictional resistance between the apex portion of the camportion 10 and the apex portion of the cam engagement portion 11 whichare brought into pressing contact with each other by the biasing forceof the engagement biasing member 12 is increased to realize the freestop. In the present embodiment, in the rotational range A2 from theposition where the joint portion 2 is opened at maximum relative to thebody portion 1 to the above-described predetermined open angle positionP2 where the joint portion is rotated in the closed position, the freestop effect is generated for holding the joint portion 2 at any desiredopen angle position relative to the body portion 1.

More specifically, the sliding convex strips 11 b each having a lengthin the rotational direction of the cam engagement portion 11 areprovided in the convex portion of the cam engagement portion 11 andsliding concave grooves 10 b with which the sliding convex strips 11 bare brought into abutment and engagement are provided in theabove-described cam portion 10 whereby the abutment area between theapex portion 10 a of the cam portion 10 and the apex portion 11 a of thecam engagement portion 11 is increased and the frictional resistancebetween the apex portion 10 a of the cam portion 10 and the apex portion11 a of the cam engagement portion 11 is enhanced.

Also, in the present embodiment, the above-described sliding convexstrips 11 b each having a length in the rotational direction of thisapex portion 11 a are provided substantially in the whole range of theapex portion 11 a of the engagement cam 11 whereby substantially in thewhole range the above-described cam portion 10 is disengaged from thecam engagement portion 11 and the apex portion 10 a of the cam portion10 and the apex portion 11 a of the cam engagement portion 11 arebrought into contact with each other, the sliding convex strips 11 b arein abutment and engagement with the sliding concave grooves 10 b underthe abutment condition.

More specifically, as shown in FIG. 11, the sliding convex strips 11 bare formed into arcuate shapes having a center at the center of the cameengagement portion 11 substantially in the middle in the diametricaldirection of the apex portion 11 a of the cam engagement portion 11 andare formed into convex strips each having a length in the rotationaldirection of the apex portion 11 a of the cam engagement portion 11.

Also, the sliding convex strips 11 b and the sliding concave grooves 10b are formed into concave and convex shapes whose substantially wholesurface portions are to be kept in abutment in the coupling engagementwhereby the abutment areas of the apex portion 10 a of the cam portion10 and the apex portion 11 a of the cam engagement portion 11 areincreased to enhance the frictional resistance to make it possible torealize an extremely excellent free stop.

Namely, in the present embodiment, the extremely excellent free stopoperation may be exhibited substantially in the whole rotational rangewhere the cam engagement portion 11 is disengaged from the cam portion10 and the apex portion 11 a of the cam engagement portion 11 and theapex portion 10 a of the cam portion 10 are brought into abutment witheach other.

Also, in the present embodiment, a rotation preventing structure portion7 is provided for releaseably engaging with the above-described closingstructure portion 5 and for preventing the closing structure portion 5from rotating in the open direction by the opening structure portion 6.

More specifically, in this rotation preventing structure portion 7, theretainer member 8 for engaging and disengaging the engagement concaveportion 9 provided in the cam engagement portion 11 is provided in thecasing 16 constituting the first joint member 3. The retainer member 8is provided slidably away from the engagement direction under therotation prevented condition through the joint member 23 and at the sametime biased in the engagement direction by the engagement biasing member22 as the coiled spring 22 for biasing in the engagement direction.

Also, the retainer member 8 is structured so that under the engagementcondition with the cam engagement portion 11, the cooperative rotationbetween the cam portion 10 and the cam engagement portion 11 by therotational biasing member 13 is prevented, at the same time, when thisretainer member 8 is disengaged from the cam engagement portion 11, thecooperative rotation between the cam portion 10 and the cam engagementportion 11 is allowed by the rotational biasing member 13, and theengagement force of the retainer member 8 to this engagement portion 11is set up to such an engagement force that the retainer member 8 is notdisengaged from the cam engagement portion 11 by the biasing force ofthe rotational biasing member 13, and when the joint portion 2 ismanually rotated in the opening direction relative to the body portion 1exceeding the predetermined open angle position P2 against the closingrotational biasing force by the cam portion 10 and the cam engagementportion 11, the retainer member 8 may be disengaged from the camengagement portion 11.

More specifically, in the retainer member 8, taper surfaces 8 a areformed at a tip end insertion portion to be inserted into the engagementconcave portion 9, and by the angle setup of these taper surfaces 8 a ,when the joint portion 2 is manually rotated in the opening directionrelative to the body portion 1 exceeding the predetermined open angleposition P2 against the closing rotational biasing force by the camportion 10 and the cam engagement portion 11, the engagement force isset up to such an engagement force that the retainer member 8 may bedisengaged from the engagement concave portion 9.

Also, in the present embodiments, contact surfaces which are innersurfaces 9 a of the engagement concave portion 9 and with which thetaper surfaces 8 a of the retainer member 8 are brought into contact arealso formed in the taper surfaces 9 a, the engagement force of theretainer member 8 relative to the engagement concave portion 9 may beselected suitably also by the angle setup of the taper surfaces 9 a ofthis engagement concave portion 9.

With such a structure, the present embodiment has the followingoperational effect.

When the second member 2 kept under the coupled and closed condition isopened to the first member 1, in the rotational range A1 from thecoupled and closed position P1 to the predetermined open angle positionP2 rotated in the open direction, the closing rotational biasing effectis generated to automatically close the second member 2 to the coupledand closed position P1 relative to the first member 1. Also, when thesecond member 2 is manually rotated in the open direction relative tothe first member 1 exceeding the predetermined open angle position P2,the open rotational biasing effect is generated to automatically openthe second member 2 up to the predetermined open angle position P3relative to the first member 1. In the rotational range A2 from theposition where the second member 2 is opened relative to the firstmember 1 to the predetermined open angle position P2 rotated in theclosing direction, the free stop effect is generated to hold the secondmember 2 in any desired open angle position relative to the first member1.

Namely, when the joint portion 2 is manually rotated in the opendirection exceeding the predetermined open angle position P2 relative tothe body portion 1, the joint portion 2 is automatically opened to thepredetermined open angle position P3. When the joint portion 2 keptunder the open condition to this predetermined open angle position P3 isrotated in the closing direction, in the rotational range A2 up to thepredetermined open angle position P2, the joint portion 2 is always keptunder the slant condition relative to the body portion 1. Exceeding thepredetermined open angle position P2, the joint portion 1 isautomatically closed to the coupled and closed position P1.

The operation of the hinge device H in this case will be described onthe basis of the drawings.

First of all, when the second joint member 4 is rotated in the directionof the arrow a in FIG. 13( b) by rotating the joint portion 2 in theopen direction relative to the body portion 1, the cam portion 10 andthe cam engagement portion 11 are cooperatively rotated in a somewhatdisengaged manner while they are to be disengaged from each other. Inthis case, before the cam portion 10 and the cam engagement portion 11are completely disengaged from each other, the retainer member 8 iscompletely disengaged from the engagement concave portion 9 of the camengagement portion 11 while being retracted in the direction indicatedby an arrow b(see FIG. 13( b)). After all, the cam portion 10 and thecam engagement portion 11 are biased by the rotational biasing member 13and are cooperatively rotated under the engagement condition in thedirection indicated by the arrow a in FIG. 13( c). Thereafter, theretainer member 8 biased by the engagement biasing member 22 is advancedagain in the direction c in FIG. 13( c) and fitted and engaged with theengagement concave portion 9 (see FIG. 13( c)).

Until the cam portion 10 and the cam engagement portion 11 arecompletely disengaged from each other, the closing rotational biasingforce for urging the joint portion 2 in the closing direction relativeto the body portion 1 is generated. After the retainer member 8 has beencompletely disengaged from the engagement concave portion 9 of the camengagement portion 11, the open rotational biasing force for urging thejoint portion 2 in the open direction relative to the body portion 1 isgenerated.

Subsequently, when the second joint member 4 is rotated in the directionindicated by an arrow d in FIG. 14( b) by rotating the joint portion 2in the closing direction relative to the body portion 1, the camengagement portion 11 is retained and held by the retainer member 8 andonly the cam portion 10 is disengaged and rotated. (In the concave andconvex engagement between the cam portion 10 and the cam engagementportion 11 in the direction in which the joint portion 2 is rotated inthe closing direction relative to the body portion 1, i.e., in thedirection in which only this cam portion 10 is rotated, the cam surfaceis set so that the engagement force of the retainer member 8 to the camengagement portion 11 exceeds this engagement force whereby this camengagement portion 11 is not cooperatively rotated but kept under therotation stop condition. Accordingly, the cam portion 10 is rotatedwhile being disengaged from the cam engagement portion 11.) In thiscase, the cam engagement portion 11 and the retainer member 8 areretracted in the direction indicated by b in FIG. 14( b) against theengagement biasing member 12 (and the engagement biasing member 22) sothat the cam portion 10 and the cam engagement portion 11 are completelydisengaged from each other (see FIG. 14( b)). Thereafter, until thesecond joint member 4 is further rotated in the direction indicated bythe arrow d in FIG. 14 against the bias of the rotational biasing member13 and the cam portion 10 and the cam engagement portion 11 are indropping engagement with each other, the free stop effect is generateddue to the frictional resistance between the apex portion 10 a of thecam portion 10 and the apex portion 11 a of the cam engagement portion11. After passing through this free stop range, the cam portion 10 andthe cam engagement portion 11 are biased by the engagement biasingmember 12 and are in dropping engagement with each other to therebygenerate the closing biasing rotational force whereby the joint portion2 is completely brought into closed condition (FIG. 14( c)).

Therefore, according to the present embodiment, in use, for example,when the finger of the hand holding the phone is inserted between thejoint portion 2 and the body portion 1 so that the joint portion 2 isrotated in the open direction relative to the body portion 1, the jointportion 2 is automatically opened due to the open rotational biasingoperation. This is extremely useful because the opening operation of thejoint portion 2 may readily and quickly be performed.

Also, in this embodiment, in the rotational range A2 from the positionP3 where the joint portion 2 is opened at maximum by the open rotationalbiasing effect relative to the body portion 1 to the predetermined openangle position P2 where the joint portion is rotated in the closingdirection, the free stop effect is generated for holding the secondmember 2 relative to the first member 1 at any desired angle portion.Accordingly, it is possible to use the phone while the joint portion 2is stopped at a desired angle at which the phone is easy to use, whichis more useful.

EMBODIMENT 2

A specific embodiment 2 of the present invention will be described withreference to FIGS. 17 to 32.

In the same manner as the above-described embodiment 1, the embodiment 2shows the case where a hinge device H according to the present inventionis applied to a collapsible type portable phone as shown in FIG. 17. Thehinge device H according to the present invention is applied to a pivotmechanism in which a body portion provided with an operating portion 14is used as a first member 1 and a joint portion provided with a displayimage field 15 is used as a second member 2 to make it possible to takethe condition from the closed condition where the first member 1 and thesecond member 2 are coupled with each other to the open condition (busycondition) where the second member 2 is rotated to, for example, 120degrees.

Then, when the second member 2 kept under the coupled and closedcondition is opened to a first member 1, in a rotational range A1 fromthe coupled and closed position P1 to a predetermined open angleposition P2 rotated in the open direction, a closing rotational biasingeffect is generated to automatically close the second member 2 to thecoupled and closed position P1 relative to the first member 1 (see FIG.32), when the second member 2 is manually rotated in the open directionrelative to the first member 1 exceeding the above-describedpredetermined open angle position P2, an open rotational biasing effectis generated to automatically open the second member 2 at once up to apredetermined open angle position P3 (maximum open angle position)relative to the first member 1 (see FIG. 32), and furthermore, in arotational range A2 from the position where the second member 2 isopened to the first member 1 to the above-described predetermined openangle position P2 rotated in the closing direction, when the hand isreleased from the second member 2, the second member 2 stops in therelease position to realize a free stop condition without any shake (seeFIG. 32).

Also, the present embodiment is composed of a first hinge body H1provided in a first pivot portion 25A provided at any one position ofright and left positions of a pivot joint portion 25 between the firstmember 1 and the second member 2 and a second hinge member H2 providedin a second pivot portion 25B provided in the other position. A closingstructure portion 5 is provided in the first hinge member H1 forgenerating a closing rotational biasing effect for automatically closingthe second member 2 to the coupled and closed position P1 relative tothe first member 1 when the second member 2 kept under the coupled andclosed condition relative to the first member 1 is opened, in arotational range A1 from the coupled and closed position P1 to apredetermined open angle position P2 rotated in the open direction. Atthe same time, an open structure portion 6 is provided in the secondhinge member H2 for generating the open rotational biasing effect forautomatically opening the second member 2 to the predetermined openangle position P3 relative to the first member 1 by urging the closingstructure portion 5 in the rotational direction. A rotation preventingstructure portion 7 is provided for releaseably engaging with theclosing structure portion 5 and for preventing the rotation of theclosing structure portion 5 by the opening structure portion 6. Adepression button portion 26 for releasing the retention of the rotationpreventing structure portion 7 to this closing structure portion 5 isprovided in the rotation preventing structure portion 7.

More specifically, in the present embodiment, mounting holes 1 b, 1 care provided in right and left portions of a proximal end of the firstmember 1, respectively. Also, mounting holes 2 b, 2 c a adjacent to andin communication with the mounting holes 1 b, 1 c are provided in rightand left portions of a proximal end of the second member 2,respectively. A hinge device H (first hinge member H1 and second hingemember H2) according to the present invention is applied as axial partsto the first pivot portion 25A and the second pivot portion 25Bconstituted by these respective mounting holes.

The first hinge member H1 will be described.

A casing 16 as a joint portion for constituting a part of a first jointmember 3 having a rotational preventing shape through theabove-described mounting hole 1 b is fixed to the body portion (firstmember). A member disposed at one end side of this casing 16 in theexposed condition as a mounting portion 17 constituting a second jointmember 4 is fixed to the joint portion 2 (second member) through themounting hole 2 b in a rotation prevented manner. This casing 16 has anoctagonal shape in cross section as shown. This is adapted to attain thefirm rotation preventing structure to the body portion 1. At the sametime, the octagonal shape is adapted as a shape which allows the partsto be received effectively in its interior while providing the rotationpreventing structure.

An axial member 18 is provided at an inner hole 17 a of theabove-described mounting portion 17 under the rotation preventedcondition to constitute the second joint member 4 provided with a camportion 10.

The axial member 18 relating to this second joint member 4 is adapted sothat the cam portion 10 is disposed rotatably within the casing 16relating to the first joint member 3.

A closing member 19 is disposed on the other end side of the casing 16relating to the first joint member 3, and furthermore, an engagementmember 20 having a cam engagement portion 11 facing and engaging the camportion 10 of the above-described second joint member 4 in a concave andconvex member is provided within the casing 16. This engagement member20 is provided rotatably within the casing 16 and at the same timeprovided slidably in the disengagement direction within the casing 16.

A coiled spring 12 for biasing in the engaging direction is provided asan engagement biasing member 12 within the casing 16 between theengagement member 20 having this cam engagement portion 11 and theclosing member 19. A tip end of this coiled spring 12 is coupled with ajoint member 23 to be described later and the cam engagement portion 11is biased in the engagement direction through this joint member 23.

When the joint portion 2 kept under the coupled and closed condition isopened to the body portion 1 by this engagement biasing member 12, inthe rotational range A1 from the coupled and closed position P1 to thepredetermined open angle position P2 rotated in the open direction, thecam portion 10 and the cam engagement portion 11 are slipped down andengaged with each other by biasing by the engagement biasing member 12so that the closing rotational biasing effect for automatically closingthe joint portion 2 up to the coupled and closed position P1 relative tothe body portion 1 is generated. (This is referred to as the closingstructure portion 5 in the claims.)

Also, when the joint portion 2 is manually rotated to the body portion 1exceeding the predetermined open angle position P2 in the openingdirection, the cam portion 10 and the cam engagement portion 11 areadapted to be rotated together under the engagement condition withoutdisengagement therebetween.

Also, the cam engagement portion 11 is structured so that V-shapedconcave portions are formed at diametrically 180 degree oppositepositions, these concave portions are used as engagement portions withwhich the above-described cam portion 10 engages, and an apex portion(end face portion) of the cam portion 10 is brought into contact with anapex portion (end face portion) between the concave portions in therange of disengagement by the pressure force by the engagement biasingmember 12.

In the present embodiment, a frictional resistance increasing means isprovided for increasing a frictional resistance between the apex portionof the cam portion 10 and the apex portion of the cam engagement portion11, and when the apex portion of the cam portion 10 and the apex portionof the cam engagement portion 11 are brought into abutment with eachother, the engagement is held at a stop position by the increase of therotational resistance due to the frictional resistance increasing meansand the pressure force of the engagement biasing member 12 so far as themembers are not moved by hands even if the rotational biasing force ofthe rotational biasing member 13 to be described later is applied.

Namely, the frictional resistance increasing means is structured so thatthe abutment area between the apex portion of the cam portion 10 and theapex portion of the cam engagement portion 11 is formed to be increased,whereby the frictional resistance between the apex portion of the camportion 10 and the apex portion of the cam engagement portion 11 whichare brought into pressing contact with each other by the biasing forceof the engagement biasing member 12 is increased to realize the freestop. In the present embodiment, in the rotational range A2 from theposition where the joint portion 2 is opened at maximum relative to thebody portion 1 to the above-described predetermined open angle positionP2 where the joint portion is rotated in the closed position, the freestop effect is generated for holding the joint portion 2 a any desiredopen angle position relative to the body portion 1.

More specifically, the sliding convex strips 11 b each having a lengthin the rotational direction of the cam engagement portion 11 areprovided in the convex portion of the cam engagement portion 11 andsliding concave grooves 10 b with which the sliding convex strips 11 bare brought into abutment and engagement are provided in theabove-described cam portion 10 whereby the abutment area between theapex portion 10 a of the cam portion 10 and the apex portion 11 a of thecam engagement portion 11 is increased and the frictional resistancebetween the apex portion 10 a of the cam portion 10 and the apex portion11 a of the cam engagement portion 11 is enhanced.

Also, in the present embodiment, the above-described sliding convexstrips 11 b each having a length in the rotational direction of thisapex portion 11 a are provided substantially in the whole range of theapex portion 11 a of the engagement cam 11 whereby substantially in thewhole range where the above-described cam portion 10 is disengaged fromthe cam engagement portion 11 and the apex portion 10 a of the camportion 10 and the apex portion 11 a of the cam engagement portion 11are brought into contact with each other, the sliding convex strips 11 bare in abutment and engagement with the sliding concave grooves 10 bunder the abutment condition.

More specifically, as shown in FIG. 29, the sliding convex strips 11 bare formed into arcuate shapes having a center at the center of the camengagement portion 11 substantially in the middle in the diametricaldirection of the apex portion 11 a of the cam engagement portion 11 andare formed into convex strips each having a length in the rotationaldirection of the apex portion 11 a of the cam engagement portion 11.

Also, the sliding convex strips 11 b and the sliding concave grooves 10b are formed into concave and convex shapes whose substantially wholesurface portions are to be kept in abutment in the coupling engagementwhereby the abutment areas of the apex portion 10 a of the cam portion10 and the apex portion 11 a of the cam engagement portion 11 areincreased to enhance the frictional resistance to make it possible torealize an extremely excellent free stop.

Namely, in the present embodiment, the extremely excellent free stopoperation may be exhibited substantially in the whole rotational rangewhere the cam engagement portion 11 is disengaged from the cam portion10 and the apex portion 11 a of the cam engagement portion 11 and theapex portion 10 a of the cam portion 10 are brought into abutment witheach other.

Also, in the present embodiment, a rotation preventing structure portion7 is provided for releaseably engaging with the above-described closingstructure portion 5 and for preventing the closing structure portion 5from rotating in the open direction by the opening structure portion 6provided in the second hinge member H2 to be described later.

More specifically, in this rotation preventing structure portion 7, theretainer member 8 for engaging and disengaging the engagement concaveportion 9 provided in the cam engagement portion 11 is provided in thecasing 16 constituting the first joint member 3. The retainer member 8is provided slidably away from the engagement direction under therotation prevented condition within the casing 16 through the jointmember 23 and at the same time biased in the engagement direction by theengagement biasing member 22 as the coiled spring 22 for biasing in theengagement direction.

Also, the retainer member 8 is structured so that under the engagementcondition with the cam engagement portion 11, the cooperative rotationbetween the cam portion 10 and the cam engagement portion 11 by therotational biasing member 13 is prevented, at the same time, when thisretainer member 8 is disengaged from the cam engagement portion 11, thecooperative rotation between the cam portion 10 and the cam engagementportion 11 is allowed by the rotational member 13, and the engagementforce of the retainer member 8 to this engagement portion 11 is set upto such an engagement force that the retainer member 8 is not disengagedfrom the cam engagement portion 11 by the biasing force of therotational biasing member 13, and when the joint portion 2 is manuallyrotated in the opening direction relative to the body portion 1exceeding the predetermined open angle position P2 against the closingrotational biasing force by the cam portion 10 and the cam engagementportion 11, the retainer member 8 may be disengaged from the camengagement portion 11.

More specifically, in the retainer member 8, tape surfaces 8 a areformed at a tip end insertion portion to be inserted into the engagementconcave portion 9, and by the angle setup of these taper surfaces 8 a,when the joint portion 2 is manually rotated in the opening directionrelative to the body portion 1 exceeding the predetermined open angleposition P2 against the closing rotational biasing force by the camportion 10 and the cam engagement portion 11, the engagement force isset up to such an engagement force that the retainer member 8 isslidingly moved against the engagement bias of the engagement biasingmember 22 so that the retainer member 8 may be disengaged from theengagement concave portion 9.

Also, in the present embodiments, contact surfaces which are innersurfaces 9 a of the engagement concave portion 9 and with which thetaper surfaces 8 a of the retainer member 8 are brought into contact arealso formed in the taper surfaces 9 a , the engagement force of theretainer member 8 relative to the engagement concave portion 9 may beselected suitably also by the angle setup of the taper surfaces 9 a ofthis engagement concave portion 9.

Also, this rotation preventing structure portion 7 is provided with thedepression button portion 26 for releasing the retention of the retainermember 8 to the above-described closing structure portion 5.

More specifically, this depression button portion 26 is structured sothat an axial portion 26 b projects from an inner center position of adepression portion 26 a having a circular shape in frontal view. Thisaxial portion 26 b is disposed to pass through an axial hole 18 aprovided in the axial member 18 relating to the second joint member 4 ina pull-apart preventing manner.

Also, the depression button portion 26 is provided with the axialportion 26 b slidable within the axial hole 18 a of the axial member 18.A tip end portion 26 b′ of the axial portion 26 b is adapted to comeinto contact with a tip end face 8 b of the above-described retainermember 8.

Accordingly, when the depression button portion 26 is operated to bedepressed, the retainer member 8 is slidingly moved against theengagement bias of the engagement biasing member 22 so that theretention to the engagement concave portion 9 provided in theabove-described cam engagement portion 11 is released.

The second hinge member H2 will be described.

A casing 28 as a joint portion constituting a part of a third jointmember 27 having a rotation preventing shape through the above-describedmounting hole 1 c is fixed to the body portion 1 (first member). Amember to be disposed in an exposed condition at one end side of thiscasing 28 is fixed in a rotation prevented manner to the joint portion 2(second member) through the mounting hole 2 c as a mounting portion 30constituting a part of a fourth joint member 29. This casing 28 has anoctagonal shape in cross section as shown. This is adapted to attain thefirm rotation preventing structure to the body portion 1. At the sametime, the octagonal shape is adapted as a shape which allows the partsto be received effectively in its interior while providing the rotationpreventing structure.

Also, a joint member 31 to be coupled with a torque spring 13 as therotational biasing member 13 is provided in a rotation preventedcondition at a tip end portion to the inner hole 30 a of theabove-described mounting portion 30. The other end portion of thisrotational biasing member 13 is coupled with a joint member 32 disposedin a rotation prevented condition at the other end portion of the casing28. Accordingly, the biasing force of the rotational biasing member 13for rotating the casing 28 functions as a biasing force for rotating thefourth joint member 29 with the casing 28 being fixed.

When the joint portion 2 is manually rotated to the body portion 1exceeding the predetermined open angle position P2 in the openingdirection by this rotational biasing member 13 relating to the secondhinge member H2, or when the depression button portion 26 is operated tobe depressed, the cam portion 10 and the cam engagement portion 11 asthe closing structure portion 5 relating to the above-described firsthinge member H1 are biased by the rotational biasing member 13 androtated together under the engagement condition without disengagementtherebetween so that the open rotational biasing effect is generated toautomatically release the joint portion 2 up to the predetermined openangle position P3 relative to the body portion 1. (This is referred toas an opening structure portion 6 in the claims.)

With such a structure, the present embodiment has the followingoperational effect.

When the second member 2 kept under the coupled and closed condition isopened to the first member 1, in the rotational range A1 from thecoupled and closed position P1 to the predetermined open angle positionP2 rotated in the open direction, the closing rotational biasing effectis generated to automatically close the second member 2 to the coupledand closed position P1 relative to the first member 1. Also, when thesecond member 2 is manually rotated in the open direction relative tothe first member 1 exceeding the predetermined open angle position P2,the open rotational biasing effect is generated to automatically openthe second member 2 up to the predetermined open angle position P3relative to the first member 1. In the rotational range A2 from theposition where the second member 2 is opened relative to the firstmember 1 to the predetermined open angle position P2 rotated in theclosing direction, the free stop effect is generated to hold the secondmember 2 in any desired open angle position relative to the first member1.

Namely, when the joint portion 2 is manually rotated in the opendirection exceeding the predetermined open angle position P2 relative tothe body portion 1, or when the depression button portion 26 is operatedto be depressed, the joint portion is automatically opened to thepredetermined open angle position P3. When the joint portion 2 keptunder the opened condition to this predetermined open angle position P3is rotated in the closing direction, in the rotational range A2 up tothe predetermined open angle position P2, the joint portion 2 is alwayskept under the slanted condition relative to the body portion 1.Exceeding the predetermined open angle position P2, the joint portion 1is automatically closed to the coupled and closed position P1.

The operation of the hinge device H in this case will be described onthe basis of the drawings.

First of all, when the retainer member 8 is slidingly moved in thedirection indicated by an arrow a in FIG. 30( b) by operating anddepressing the depression button portion 26 relating to the first hingemember H1, the cam portion 10 and the cam engagement portion 11 arecooperatively rotated by the open rotational biasing force of theopening structure portion 6 (rotational biasing member 13) relating tothe second hinge member H2 under the concave and convex engagementcondition. In this case, since the retainer member 8 is always biased tobe engaged by the engagement biasing member 22, after the cam portion 10and the cam engagement portion 11 have been cooperatively rotatedthrough about 180 degrees, the retainer member 8 is again engaged withthe engagement concave portion 9 of the cam engagement portion 11 (seeFIG. 30( c)).

Subsequently, when the second joint member 4 is rotated in the directionindicated by an arrow d in FIG. 31( b) by rotating the joint portion 2in the closing direction relative to the body portion 1, the camengagement portion 11 is retained and held by the retainer member 8 andonly the cam portion 10 is disengaged and rotated. In this case, the camengagement portion 11 and the retainer member 8 are retracted in thedirection a in FIG. 31( b) against the engagement biasing member 12 (andthe engagement biasing member 22) and the cam portion 10 and the camengagement portion 11 are completely disengaged from each other (seeFIG. 31( b)). Thereafter, while the second joint member 4 is furtherrotated against the bias of the rotational biasing member 13 in thedirection indicated by the arrow d in FIG. 31( c) and the cam portion 10and the cam engagement portion 11 are in dropping engagement with eachother, a free stop effect is generated due to the friction resistancebetween the apex portion 10 a of the cam portion 10 and the apex portion11 a of the cam engagement portion 11. After this free stop range, thecam portion 10 and the cam engagement portion 11 are biased by theengagement biasing member 12 and in dropping engagement with each otherto generate the closing biasing rotational force to thereby bring thejoint portion 2 to the completely closed condition to the body portion 1(see FIG. 31( c)).

Next, the operation of the hinge device H in the case where the jointportion 2 is manually opened to the body portion 1 will be described.

First of all, when the second joint member 4 is rotated by rotating thejoint portion 2 in the open direction relative to the body portion 1,the cam portion 10 and the cam engagement portion 11 are cooperativelyrotated in a somewhat disengaged manner while they are to be disengagedfrom each other. In this case, before the cam portion 10 and the camengagement portion 11 are completely disengaged from each other, theretainer member 8 is completely disengaged from the engagement concaveportion 9 of the cam engagement portion 11 while being retracted.Thereafter, the retainer member 8 biased by the engagement biasingmember 22 is advanced again and fitted and engaged with the engagementconcave portion 9.

Until the cam portion 10 and the cam engagement portion 11 arecompletely disengaged from each other, the closing rotational biasingforce for urging the joint portion 2 in the closing direction relativeto the body portion 1 is generated. After the retainer member 8 has beencompletely disengaged from the engagement concave portion 9 of the camengagement portion 11, the open rotational biasing force for urging thejoint portion 2 in the open direction relative to the body portion 1 isgenerated.

Subsequently, when the second joint member 4 is rotated by rotating thejoint portion 2 in the closing direction relative to the body portion 1,the cam engagement portion 11 is retained and held by the retainermember 8 and only the cam portion 10 is disengaged and rotated. (In theconcave and convex engagement between the cam portion 10 and the camengagement portion 11 in the direction in which the joint portion 2 isrotated in the closing direction relative to the body portion 1, i.e.,in the direction in which only this cam portion 10 is rotated, the camsurface is set so that the engagement force of the retainer member 8 tothe cam engagement portion 11 exceeds this engagement force whereby thiscam engagement portion 11 is not cooperatively rotated but kept underthe rotation stop condition. Accordingly, the cam portion 10 is rotatewhile being disengaged from the cam engagement portion 11.) In thiscase, the cam engagement portion 11 and the retainer member 8 areretracted against the engagement biasing member 12 (and the engagementbiasing member 22). Thereafter, until the second joint member 4 isfurther rotated against the bias of the rotational biasing member 13 andthe cam portion 10 and the cam engagement portion 11 are in droppingengagement with each other, the free stop effect is generated due to thefrictional resistance between the apex portion 10 a of the cam portion10 and the apex portion of the cam engagement portion 11. After passingthrough this free stop range, the cam portion 10 and the cam engagementportion 11 are biased by the engagement biasing member 12 and are indropping engagement with each other to thereby generate the closingbiasing power whereby the joint portion 2 is completely brought intoclosed condition.

Therefore, according to the present embodiment, in use, for example,when the finger of the hand holding the phone is inserted between thejoint portion 2 and the body portion 1 so that the joint portion 2 irotated in the open direction relative to the body portion 1, or thedepression button portion 26 is operated to be depressed, the jointportion 2 is automatically opened due to the open rotational biasingoperation. This is extremely useful because the opening operation of thejoint portion 2 may readily and quickly be performed.

Also, in this embodiment, in the rotational from the position P3 wherethe joint portion 2 is opened at maximum by the open rotational biasingeffect relative to the body portion 1 to the predetermined open angleposition P2 where the joint portion is rotated in the closing direction,the free stop effect is generated for holding the second member 2relative to the first member 1 at any desired angle portion.Accordingly, it is possible to use the phone while the joint portion 2is stopped at a desired angle at which the phone is easy to use, whichis more useful.

Also, in the present embodiment, the hinge device H disposed to thepivotal joint portion 25 between the body portion 1 and the jointportion 2 is the hinge structure (double hinge structure) composed ofthe first hinge member H1 provided with the closing structure portion 5and the rotation preventing structure portion 7 and the second hingemember H2 provided with the opening structure portion 6. Therefore, thepivotal joint portion 25 between the body portion 1 and the jointportion 2 for providing this hinge device H may be divided on the rightand left sides and each pivotal portion (first pivotal portion 25A andsecond pivotal portion 25B) may be made small in size. Since a vacantspace S may be formed between the right and left pivot portions (betweenthe first pivot portion 25A and the second pivot portion 25B), thisvacant space S serves to keep a sufficient space suitable for arrangingwirings for electrically connecting electronic parts to be disposedwithin the joint portion 2 and electronic parts to be disposed withinthe body portion 1. Such effect and the like may be ensured.

The other is the same as those of the embodiment 1.

Incidentally, the present invention is not limited to or by theembodiments 1, 2 but the specific structure of each component may bedesigned as desired.

1. A hinge device for rotatably pivoting a first member and a secondmember open and closed, said hinge device comprising: a first hingemember provided in a first pivot portion provided in either one of aright and a left side of a pivot joint portion between said first memberand said second member and a second hinge member provided in a secondpivot portion provided opposite the first pivot portion, wherein saidfirst hinge member comprises a first joint member coupled to the firstmember or the second member and a second joint member coupled to thesecond member or the first member, wherein when said first joint memberis coupled to said first member, said second joint member is coupled tosaid second member and vice-versa; a cam portion operatively connectedto either one of the first joint member and the second joint member ofsaid first hinge member; a cam engagement portion which engages with thecam portion operatively connected to the other of the first joint memberand the second joint member of said first hinge member not connected tothe cam portion; at least one of the cam portion and the cam engagementportion adapted to slidably move in an engagement and disengagementdirection; an engagement biasing member for biasing at least one of thecam portion and the cam engagement portion in the engagement direction;wherein when the second member is in a coupled and closed position andis rotated from the coupled and closed position to a predetermined openangle position the cam portion and the cam engagement portion are biasedby said engagement biasing member and engage each other whereby aclosing rotation biasing effect is generated to automatically urge thesecond member to the coupled and closed position; a rotational biasingmember in said second hinge member operatively connected to at least oneof said cam portion and said cam engagement portion for biasing at leastone of the cam portion and the cam engagement portion in a rotationaldirection; wherein the cam portion and the cam engagement portion arebiased by the rotational biasing member and are not disengaged from eachother but rotated together so that an open rotational biasing effect isgenerated to automatically open the second member to a secondpredetermined open angle position; and a retainer member for releaseablyengaging said cam portion or the cam engagement portion provided ineither one of said first joint member and said second joint member ofsaid first hinge member; and wherein when the retainer member is engagedat the cam portion or the cam engagement portion, the cooperativerotation of the cam portion and the cam engagement portion by saidrotational biasing member is prevented; and wherein when the retainermember is disengaged from the cam portion or the cam engagement portion,the cooperative rotation between the cam portion and the cam engagementportion by the rotational biasing member is allowed, wherein saidretainer member is slidingly moved by depressing a button provided ineither one of the first joint member and the second joint member so thatthe engagement to said cam portion or the cam engagement portion isreleased.
 2. An electronic device incorporating the hinge deviceaccording to claim 1, wherein a body portion provided with an operatingportion and a joint portion provided with a display image field arecoupled with each other and disposed to cover the operating portion whensaid operating portion is not operative, said hinge device rotatablycoupling said body portion and said joint portion so that said jointportion rotates to expose the operating portion or the joint portion maybe rotated around its own axis and wherein said body portion comprisessaid first member or said second member and said joint portion comprisessaid second member or said first member in said hinge device.
 3. A hingedevice for rotatably pivoting a first member and a second member openedand closed, said hinge device comprising: a first hinge member providedin a first pivot portion provided in either one of a right and a leftside of a pivot joint portion between said first member and said secondmember and a second hinge member provided in a second pivot portionprovided opposite the first pivot portion wherein said first hingemember comprises a first joint member coupled to the first member or thesecond member and a second joint member coupled to the second member orthe first member, wherein when said first joint member is coupled to thesecond member or the first member, wherein when said first joint memberis coupled to said first member, said second joint member is coupled tosaid second member and vice-versa; a cam portion operatively connectedto either one of the first joint member and the second joint member ofsaid first hinge member; a cam engagement portion which engages with thecam portion operatively connected to the other of the first joint memberand the second joint member of said first hinge member not connected tothe cam portion; at least one of the cam portion and the cam engagementportion adapted to slidably move in an engagement and disengagementdirection; an engagement biasing member for biasing at least one of thecam portion and the cam engagement portion in the engagement direction;wherein when the second member is in a coupled and closed position andis rotated from the coupled and closed position to a predetermined openangle position the cam portion and the cam engagement portion are biasedby said engagement biasing member and engage each other whereby aclosing rotation biasing effect is generated to automatically urge thesecond member to the coupled and closed position; a rotational biasingmember in said second hinge member operatively connected to at least oneof said cam portion and said cam engagement portion for biasing at leastone of the cam portion and the cam engagement portion in a rotationaldirection; wherein the cam portion and the cam engagement portion arebiased by the rotational biasing member and are not disengaged from eachother but rotated together so that an open rotational biasing effect isgenerated to automatically open the second member to a secondpredetermined open angle position; wherein in a rotational range to thepredetermined open angle position rotated in the closing direction fromthe second predetermined open angle position the cam portion and the camengagement portion are disengaged from each other; an apex portion ofthe cam portion and an apex portion of the cam engagement portion urgedin abutment with each other by the bias of the engagement biasing memberto generate a frictional resistance for holding the second member to thefirst member at any desired open angle position; and a retainer memberfor releaseably engaging said cam portion or the cam engagement portionis provided in either one of said first joint member and said secondjoint member of said first hinge member; and wherein when the retainermember is engaged at the cam portion or the cam engagement portion, thecooperative rotation of the cam portion and the cam engagement portionby said rotational biasing member is prevented; and wherein when theretainer member is disengaged from the cam portion or the cam engagementportion, the cooperative rotation between the cam portion and the camengagement portion by the rotational biasing member is allowed and, saidretainer member is slidingly moved by depressing a button provided ineither one of the first joint member and the second joint member so thatthe engagement to said cam portion or the cam engagement portion isreleased.
 4. An electronic device incorporating the hinge deviceaccording to claim 3, wherein a body portion provided with an operatingportion and a joint portion provided with a display image field arecoupled with each other and disposed to cover the operating portion whensaid operating portion is not operative, said hinge device rotatablycoupling said body portion and said joint portion so that said jointportion rotates to expose the operating portion or the joint portion maybe rotated around its own axis and wherein said body portion comprisessaid first member or said second member and said joint portion comprisessaid second member or said first member in said hinge device.
 5. A hingedevice for rotatably pivoting a first member and a second member openedand closed, said hinge device comprising: a first hinge member providedin a first pivot portion provided in either one of a right and a leftside of a pivot joint portion between said first member and said secondmember and a second hinge member provided in a second pivot portionprovided opposite the first pivot portion, wherein said first hingemember comprises a first joint member coupled to the first member or thesecond member and a second joint member coupled to the second member orthe first member, wherein when said first joint member is coupled tosaid first member, said second joint member is coupled to said secondmember and vice-versa; a cam portion operatively connected to either oneof the first joint member and the second joint member of said firsthinge member; a cam engagement portion which engages with the camportion operatively connected to the other of the first joint member andthe second joint member of said first hinge member not connected to thecam portion; at least one of the cam portion and the cam engagementportion adapted to slidably move in an engagement and disengagementdirection; an engagement biasing member for biasing at least one of thecam portion and the cam engagement portion in the engagement direction;wherein when the second member is in a coupled and closed position andis rotated from the coupled and closed position to a predetermined openangle position the cam portion and the cam engagement portion are biasedby said engagement biasing member and engage each other whereby aclosing rotation biasing effect is generated to automatically urge thesecond member to the coupled and closed position; a rotational biasingmember in said second hinge member operatively connected to at least oneof said cam portion and said cam engagement portion for biasing at leastone of the cam portion and the cam engagement portion in a rotationaldirection; wherein when the second member is manually rotated in a rangeexceeding the predetermined open angle position, the cam portion and thecam engagement portion are biased by the rotational biasing member andare not disengaged from each other but rotated together so that an openrotational biasing effect is generated to automatically open the secondmember to a second predetermined open angle position; and a retainermember for releaseably engaging said cam portion or the cam engagementportion provided in either one of said first joint member and saidsecond joint member of said first hinge member, wherein when theretainer member engages the cam portion or the cam engagement portion,the cooperative rotation of the cam portion and the cam engagementportion by said rotational biasing member is prevented; and wherein whenthe retainer member is disengaged from the cam portion or the camengagement portion cooperative rotation between the cam portion and thecam engagement portion by the rotational biasing member is allowed; andwherein a retention force of the retainer member to said cam portion orsaid cam engagement portion is established such that the retainer memberis not disengaged from the cam portion or the cam engagement portion bythe biasing force of said rotational biasing member and wherein theretainer member may be disengaged from the cam portion or the camengagement portion when the second member is manually rotated in a rangeexceeding the predetermined open angle position against the closingrotational biasing force by said cam portion and said cam engagementportion relative to said first member.
 6. The hinge device according toclaim 5, further characterized in that an engagement concave portion forfitting and retaining said retainer member is provided in said camportion or said cam engagement portion, and a taper surface is formed inan insertion portion of the retainer member to be inserted into saidengagement concave portion whereby a retention force between theretainer member and said engagement concave portion is established suchthat the retainer member is disengaged from the cam portion or the camengagement portion when the second member is manually rotated relativeto the first member in the open direction exceeding the predeterminedopen angle position against the closing rotation biasing force by thecam portion and the cam engagement portion.
 7. An electronic deviceincorporating the hinge device according to claim 6, wherein a bodyportion provided with an operating portion and a joint portion providedwith a display image field are coupled with each other and disposed tocover the operating portion when said operating portion is notoperative, said hinge device rotatably coupling said body portion andsaid joint portion so that said joint portion rotates to expose theoperating portion or the joint portion may be rotated around its ownaxis and wherein said body portion comprises said first member or saidsecond member and said joint portion comprises said second member orsaid first member in said hinge device.
 8. An electronic deviceincorporating the hinge device according to claim 5, wherein a bodyportion provided with an operating portion and a joint portion providedwith a display image field are coupled with each other and disposed tocover the operating portion when said operating portion is notoperative, said hinge device rotatably coupling said body portion andsaid joint portion so that said joint portion rotates to expose theoperating portion or the joint portion may be rotated around its ownaxis and wherein said body portion comprises said first member or saidsecond member and said joint portion comprises said second member orsaid first member in said hinge device.
 9. A hinge device for rotatablypivoting a first member and a second member open and closed, said hingedevice comprising: a first hinge member provided in a first pivotportion provided in either one of a right and a left side of a pivotjoint portion between said first member and said second member and asecond hinge member provided in a second pivot portion provided oppositethe first pivot portion, wherein said first hinge member comprises afirst joint member coupled to the first member or the second member anda second joint member coupled to the second member or the first member,wherein when said first joint member is coupled to said first member,said second joint member is coupled to said second member andvice-versa; a cam portion operatively connected to either one of thefirst joint member and the second joint member of said first hingemember; a cam engagement portion which engages with the cam portionoperatively connected to the other of the first joint member and thesecond joint member of said first hinge member not connected to the camportion; at least one of the cam portion and the cam engagement portionadapted to slidably move in an engagement and disengagement direction;an engagement biasing member for biasing at least one of the cam portionand the cam engagement portion in the engagement direction, wherein whenthe second member is in a coupled and closed position and is rotatedfrom the coupled and closed position to a predetermined open angleposition the cam portion and the cam engagement portion are biased bysaid engagement biasing member and engage each other whereby a closingrotation biasing effect is generated to automatically urge the secondmember to the coupled and closed position; a rotational biasing memberin said second hinge member operatively connected to at least one ofsaid cam portion and said cam engagement portion for biasing at leastone of the cam portion and the cam engagement portion in a rotationaldirection, wherein when the second member is manually rotated in a rangeexceeding the predetermined open angle position, the cam portion and thecam engagement portion are biased by the rotational biasing member andare not disengaged from each other but rotate together so that an openrotational biasing effect is generated to automatically open the secondmember to a second predetermined open angle position and wherein in arotational range to the predetermined open angle position rotated in theclosing direction from the second predetermined open angle position, thecam portion and the cam engagement portion are disengaged from eachother; an apex portion of the cam portion and an apex portion of the camengagement portion urged in abutment with each other by the bias of theengagement biasing member to generate a frictional resistance forholding the second member to the first member at any desired open angleposition; and a retainer member for releaseably engaging said camportion or the cam engagement portion provided in either one of saidfirst joint member and said second joint member of said first hingemember and wherein when the retainer member is engaged with the camportion or the cam engagement portion, the cooperative rotation of thecam portion and the cam engagement portion by said rotational biasingmember is prevented and wherein when the retainer member is disengagedfrom the cam portion or the cam engagement portion, the cooperativerotation between the cam portion and the cam engagement portion by therotational biasing member is allowed and wherein a retention force ofthe retainer member to said cam portion or said cam engagement portionis established such that the retainer member is not disengaged from thecam portion or the cam engagement portion by the biasing force of saidrotational biasing member wherein the retainer member may be disengagedfrom the cam portion or the cam engagement portion when the secondmember is manually rotated in a range exceeding the predetermined openangle position against the closing rotational biasing force by said camportion and said cam engagement portion relative to said first member.10. The hinge device according to claim 9, wherein an engagement concaveportion for fitting and retaining said retainer member is provided insaid cam portion or said cam engagement portion, and a taper surface isformed in an insertion portion of the retainer member to be insertedinto said engagement concave portion whereby a retention force betweenthe retainer member and said engagement concave portion is establishedsuch that the retainer member is disengaged from the cam portion or thecam engagement portion when the second member is manually rotatedrelative to the first member in the open direction exceeding thepredetermined open angle position P2 against the closing rotationbiasing force by the cam portion and the cam engagement portion.
 11. Anelectronic device incorporating the hinge device according to claim 9,wherein a body portion provided with an operating portion and a jointportion provided with a display image field are coupled with each otherand disposed to cover the operating portion when said operating portionis not operative, said hinge device rotatably coupling said body portionand said joint so that said joint portion rotates to expose theoperating portion or the joint portion may be rotated around its ownaxis and wherein said body portion comprises said first member or saidsecond member and said joint portion comprises said second member orsaid first member in said hinge device.